metric grain
A jeweler carefully weighs a single pearl on a scale calibrated in metric grains.
Noun: A unit of mass equal to 50 milligrams, traditionally used for weighing pearls and diamonds. It is equivalent to one-quarter of a metric carat.
The term "metric grain" is a specific, technical unit of measurement. It is primarily used in the context of gemology and jewelry, particularly for valuing and describing very small, precious items like pearls and diamonds. - The pearl's weight was recorded as four metric grains. - Diamond prices are often calculated per metric grain for very small stones.
- Historical Context: The "grain" as a unit has a long history in various measurement systems (e.g., troy weight, avoirdupois). The "metric grain" represents its standardized definition within the metric system for the gem trade.
- Precision in Trade: Its use signifies a need for high precision in transactions involving high-value, low-mass objects.
- Carat (metric): A unit of mass equal to 200 milligrams. One metric carat is equivalent to four metric grains.
- Milligram (mg): A standard metric unit of mass. One metric grain is equal to 50 milligrams.
- Fifty milligrams: The direct metric equivalent.
- Quarter carat: Describes the same mass in relation to the standard gem weight unit.
This is a highly specialized term. In most modern scientific or general contexts, mass would be expressed directly in milligrams or carats. The term "metric grain" persists in specific professional jargon within the jewelry industry.
A jeweler carefully weighs a single pearl on a scale calibrated in metric grains.
- a weight unit used for pearls or diamonds: 50 mg or 1/4 carat